A screengrab shows a woman ranting against black and Polish people on a Croydon to Wimbledon tram. Photograph: YouTube

The video of the woman ranting against black and Polish people ("What has this country come to? ... with loads of black people and load of fucking Polish") on the Croydon to Wimbledon tram has caused quite a stir, generating quite a storm on social media and swiftly leading to an arrest. But I have to say it strikes me as one of the less shocking videos I've seen in my lifetime. Compared to footage of guys filming themselves attacking "pakis" on the tube, the storm over this video (which contains explicit comments some viewers may find offensive) looks no worse than an argument over whether X Factor tweeters should be publicly flogged or not.

In fact, it reminded me a little of the brilliant sketch by Stewart Lee where his nan says: "It's political correctness gawn mad Stew". I can imagine the woman leaving the tram complaining that she couldn't even talk about immigration in her own country.

Still, I was indignant about the incident until I saw the backlash on Twitter. Piers Morgan was calling for the woman to be deported, some asked for her to be locked up, while others said her child should be taken away. And those are only the printable responses.

I hate to write an article defending such a woman but I think calling for her to be arrested and then prosecuted is over the top. I don't think such behaviour is acceptable or have a problem with condemning it. My issue is that calling for the law to get involved is about the worst way to deal with such incidents. And there are several reasons for this.

First, the law has little impact. The Race Relations Act made it illegal for organisations to discriminate but you can count the number of successful prosecutions on your fingers. It works much better in tightly defined instances of outright discrimination rather than hate speech.

What actually changed attitudes against racism was a shift in popular culture pushed by brave people. The people who joined together in solidarity against skinheads (at Cable Street in the 30s and Southall in the 80s) changed attitudes. Rock Against Racism shifted popular attitudes. Love Music Hate Racism changed attitudes. The Anti-Nazi League did. But trying to push for better social attitudes through the law is a futile task. Popular condemnation and viral piss-takes work far better instead.

Second, you may argue she can already be prosecuted under the Public Order Act or a "breach of the peace" but the law is currently an overbearing ass. It allows the police to make an arrest if someone feels "insulted". The same laws allow them to detain political activists and make arbitrary arrests.

In short, the very law that some people are cheering here can easily be used against them. Do you really want to give police the willingness to arrest people simply for having an argument?

Third, laws that criminalise hate speech almost always backfire on minorities themselves. A few years ago British Muslim organisations campaigned vigorously for a law against religious hatred, hoping it would stop the BNP from using them as electoral fodder. Labour passed the law but it did little to stop the BNP. Instead, most of the people prosecuted under the law were – you guessed it – Muslims.

I have no problems with laws against outright discrimination. But when crafted against inciting hatred or "breaching the peace" – they almost always work against minorities and other vulnerable people rather than for them.

And let's be honest, the woman was just sitting there with a child on her lap. She offended people but posed no threat and didn't harm anyone (the person behind her had to be calmed down or it could have turned a lot uglier). It isn't the same as a group of drunken blokes swearing in a train carriage and to criminalise simply being offensive or swearing in public would have half of Britain in jail.

My fourth argument is simply this: I would rather a world where such incidents didn't exists but the world will never be perfect. I would much prefer such racism to be open and visible because there are still far too many Westminster commentators who think racism is a thing of the past.

There are still far too many reporters at tabloids who think their biased reporting doesn't have an impact. It does, and this woman is a product of the opinions of the rightwing press.

You may ask how I would have responded if I was there. Like the other woman, I would say what I've said for years – I'm English whether racists like it or not. Then I'd go back to pretending to playing games on my phone like most people in that carriage.